This Is Us: Sam Trammell warns the tension between Ben, Rebecca, and Jack turns up 'more than one notch'

[Warning: This story contains plot details from Tuesday’s episode of This Is Us, “Jack Pearson’s Son.”]

The Rebecca-Jack relationship is not only at the emotional core of This Is Us, it’s sacred ground to fans of the NBC dramedy. Enter this restricted area — which is guarded by dogs, barbed wire, and lasers — at your own risk. (See: Early fan reaction to Miguel, Jack’s best friend who’s been married to Rebecca for an indeterminate period of time.)

The latest man to venture bravely into hallowed territory is Ben, Rebecca’s old bandmate who reappeared in last week’s episode. As we — and Jack — learned in this episode, the connection between Ben and Rebecca (Mandy Moore) wasn’t just restricted to the notes in a treble clef; they used to date when Rebecca was 19 years old. At a time in the ’90s when Jack (Milo Ventimiglia) and Rebecca’s bond has been tested — and from the looks of a drink-downing Jack at the end of Tuesday’s Valentine’s Day-set story, plus Rebecca’s “I need to have something for myself without you getting in the way” heat-of-conflict admission, it’s about to be put under a helluva lot more stress — Jack clearly feels threatened by Ben, as well as Rebecca’s decision to pursue some mothballed musical dreams and embark on a five-state tour with his jazz group.

Before the band hits the road, let’s check in with the man who plays the man who plays the keys, as well as the man who plays a key role in Jack and Rebecca’s marital discord: True Blood vet Sam Trammell.

ENTERTAINMENT WEEKLY: So… I don’t know how much you know about this Jack and Rebecca relationship, but the fans are known on occasion to have a somewhat passionate opinion about them. How did you feel about signing on to play a source of tension in their marriage? And are you prepared for hate mail and tweets?SAM TRAMMELL: I mean, I’m terrified, frankly. I’ve heard that fans are extraordinarily supportive and loyal to that couple, and I completely understand it and empathize with them. I watch the show, and they’re an amazing couple, and Jack is like the ultimate father/husband. He sets the bar so high, you know? He’s wonderful! So, of course, any kind of person that might create tension I can imagine might get the ire of a lot of fans. Yeah, it could be really bad. Am I prepared? Probably not. [Laughs.]

Have you talked with Jon Huertas [a.k.a Miguel] about forming a support group for the men who play Rebecca’s past or future romantic partners?That is a fantastic idea. I saw him once when I was working and met him. He’s a great guy. But yeah, I think we will. We’re going to have to join together, just to survive the flurry.

What was your first reaction when you were asked to join the show, and how much of Ben’s story were you told at the time?I just think this show is one of the highest-quality shows being written out there. The writing’s amazing, the acting’s amazing, so I had a lot of respect for it. I was immediately interested and excited about it. And I was told a fair amount by one of the writers, but this was way back in October, so they were still figuring things out. But they were excited about my arc.

You were in bands growing up and played the piano. But in this episode, you’re also singing. Did you used to sing? And if not, did Mandy offer up any advice?I have never sung until this episode. Music had been part of my life growing up, so my agent asked if I would sing, and I said, “I just don’t sing,” because I was scared about taking that on. But then I felt like, “Aw, I probably should’ve said I could, because I probably can. I don’t know.” And then [This Is Us executive producer/director] Ken Olin called me the next day and said, “Do you just want to try it out? If it doesn’t work, we’ll cut it.” And I was like, “Yes! I definitely want to try it out! Yes! I’m so glad you called!”

I got a singing coach and worked on it. I worked with the composer who lowered the key of it to fit with my voice register. I worked on it, worked on it, and we got up there on the day of, and Mandy wanted it to sing it in a higher key [laughs], so the composer agreed to do that and winked at me and said, “Don’t worry, you’ll be fine,” and I was like, “Oh, god!” I sat and watched her sing in the booth, which was incredible because she’s very talented. Then she came in and she sat and watched me, which was slightly nerve-wracking, but I somehow pulled it off. That singing coach was very helpful. We shot it the next day, and they played the track, and you sing over it, and it was so fun. We got to look at each other while we were singing — it was a total blast.

Rebecca and Ben do some passionate singing together on Etta James’ “Bring it on Home to Me” with lyrics like “If you ever change your mind about leavin’/leavin’ me behind/Oh, oh, bring it to me/ Bring your sweet lovin’.” There’s some meaning to be read into that about the past, if you want to. Miguel assures Jack that they’re just playing it up for the crowd. But is their connection stronger than just a musical one? That eye contact is intense. It might not even be malicious on Ben’s part, or maybe not even something that Ben is willing to admit to himself.I would agree. Ben’s a human being, Rebecca is beautiful and very talented, and that song is a sexy song. I think there definitely is some attraction at that point. You just can’t help it. I would say for Ben, there is a little more. It starts off very much like, “Join the band, help us out because we’re floundering,” she helps out, we start doing really well. But then it’s one of those things where it’s like summer camp — you start spending a lot of time with someone, things change a little bit, and yeah, for Ben it’s probably not strictly platonic at that moment when they’re singing, because it’s, you know, sexy. But I say to Jack that she’s beautiful, and she’s so talented, and he’s a lucky man. So that says it all right there.

NEXT PAGE: Trammell answers the question: How much should we trust Ben?